At present, three component valves such as those used for propane gas barbecue grills are commonly assembled by hand in factories. Such labor intensive operations are costly and time consuming.
Previous devices have been devised to assist in rotating threaded objects together to a predetermined level of torque resistance. See for example U.S. Pat. No. 3,382,559 Kopec, et al. issued May 14, 1968. Such apparatus, however, is not capable of accurately aligning parts to a predetermined orientation because of variations in torque between the components resulting in slight irregularities in the manufacturing processes for those components. A need has thus continued to exist for apparatus capable of completing the assembly of threaded parts to a desired depth and desired final orientation.
An object of the present invention is to provide a power assisted device for completing the assembly of two or more threaded members requiring an accurately controlled predetermined final orientation of the threaded components.
A further object of the invention is to provide novel apparatus for holding one component of a threaded-together assembly in a stationary position, while threading thereon, from opposite sides or directions, other component members. A still further object of the invention is to provide a device wherein the motion of the thread rotating device is controlled by the position of the members being threaded together. Another aspect of the invention relates to the provision of such apparatus wherein the amount of rotation of the member being threaded together signals the stoppage of the assembly equipment, so that a predetermined rotational alignment of the members is provided.
These and other objects and advantages are achieved by providing power driven apparatus for assembling two or more threadedly engaged workpiece members to a predetermined degree of threaded coupling and a predetermined orientation which includes, a clamping unit to securely engage and hold one of the threaded members in a fixed rotational position in a cradling member, there being a clamping member having a yoke adapted to pivot against a workpiece component and clamp it in the cradle member. One or more power driven rotatable yoke means are movable toward and away from said clamping unit, the rotatable yoke means having a control means to position them in a predetermined rotational orientation to engage another rotatable workpiece component when the rotatable component is advanced toward the workpiece. Motor means are provided to rotate the driving yoke component to thread said workpiece components together. Means activated by the position of said workpiece and coupled to said drive mechanism are provided to stop the rotation when the workpiece components have been threaded together to a desired degree in a predetermined orientation relative to each other.
The foregoing and other objects and advantages of the present invention will be apparent from the following detailed description and accompanying drawings.